#ifndef HASH_CRC_H_
#define HASH_CRC_H_

typedef unsigned short CRC16_CTX;
typedef unsigned short CRC16CCITT_CTX;
typedef unsigned long CRC32_CTX;


static const unsigned short crc16tab[] = /* CRC lookup table */
{
	0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
		0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
		0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
		0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
		0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
		0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
		0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
		0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
		0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
		0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
		0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
		0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
		0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
		0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
		0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
		0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
		0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
		0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
		0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
		0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
		0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
		0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
		0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
		0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
		0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
		0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
		0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
		0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
		0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
		0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
		0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
		0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
};

// CRC-32 polynominal:
// X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X+1

static unsigned long crc32tab[] = {
	0x00000000L, 0x77073096L, 0xEE0E612CL, 0x990951BAL,
		0x076DC419L, 0x706AF48FL, 0xE963A535L, 0x9E6495A3L,
		0x0EDB8832L, 0x79DCB8A4L, 0xE0D5E91EL, 0x97D2D988L,
		0x09B64C2BL, 0x7EB17CBDL, 0xE7B82D07L, 0x90BF1D91L,
		0x1DB71064L, 0x6AB020F2L, 0xF3B97148L, 0x84BE41DEL,
		0x1ADAD47DL, 0x6DDDE4EBL, 0xF4D4B551L, 0x83D385C7L,
		0x136C9856L, 0x646BA8C0L, 0xFD62F97AL, 0x8A65C9ECL,
		0x14015C4FL, 0x63066CD9L, 0xFA0F3D63L, 0x8D080DF5L,
		0x3B6E20C8L, 0x4C69105EL, 0xD56041E4L, 0xA2677172L,
		0x3C03E4D1L, 0x4B04D447L, 0xD20D85FDL, 0xA50AB56BL,
		0x35B5A8FAL, 0x42B2986CL, 0xDBBBC9D6L, 0xACBCF940L,
		0x32D86CE3L, 0x45DF5C75L, 0xDCD60DCFL, 0xABD13D59L,
		0x26D930ACL, 0x51DE003AL, 0xC8D75180L, 0xBFD06116L,
		0x21B4F4B5L, 0x56B3C423L, 0xCFBA9599L, 0xB8BDA50FL,
		0x2802B89EL, 0x5F058808L, 0xC60CD9B2L, 0xB10BE924L,
		0x2F6F7C87L, 0x58684C11L, 0xC1611DABL, 0xB6662D3DL,
		0x76DC4190L, 0x01DB7106L, 0x98D220BCL, 0xEFD5102AL,
		0x71B18589L, 0x06B6B51FL, 0x9FBFE4A5L, 0xE8B8D433L,
		0x7807C9A2L, 0x0F00F934L, 0x9609A88EL, 0xE10E9818L,
		0x7F6A0DBBL, 0x086D3D2DL, 0x91646C97L, 0xE6635C01L,
		0x6B6B51F4L, 0x1C6C6162L, 0x856530D8L, 0xF262004EL,
		0x6C0695EDL, 0x1B01A57BL, 0x8208F4C1L, 0xF50FC457L,
		0x65B0D9C6L, 0x12B7E950L, 0x8BBEB8EAL, 0xFCB9887CL,
		0x62DD1DDFL, 0x15DA2D49L, 0x8CD37CF3L, 0xFBD44C65L,
		0x4DB26158L, 0x3AB551CEL, 0xA3BC0074L, 0xD4BB30E2L,
		0x4ADFA541L, 0x3DD895D7L, 0xA4D1C46DL, 0xD3D6F4FBL,
		0x4369E96AL, 0x346ED9FCL, 0xAD678846L, 0xDA60B8D0L,
		0x44042D73L, 0x33031DE5L, 0xAA0A4C5FL, 0xDD0D7CC9L,
		0x5005713CL, 0x270241AAL, 0xBE0B1010L, 0xC90C2086L,
		0x5768B525L, 0x206F85B3L, 0xB966D409L, 0xCE61E49FL,
		0x5EDEF90EL, 0x29D9C998L, 0xB0D09822L, 0xC7D7A8B4L,
		0x59B33D17L, 0x2EB40D81L, 0xB7BD5C3BL, 0xC0BA6CADL,
		0xEDB88320L, 0x9ABFB3B6L, 0x03B6E20CL, 0x74B1D29AL,
		0xEAD54739L, 0x9DD277AFL, 0x04DB2615L, 0x73DC1683L,
		0xE3630B12L, 0x94643B84L, 0x0D6D6A3EL, 0x7A6A5AA8L,
		0xE40ECF0BL, 0x9309FF9DL, 0x0A00AE27L, 0x7D079EB1L,
		0xF00F9344L, 0x8708A3D2L, 0x1E01F268L, 0x6906C2FEL,
		0xF762575DL, 0x806567CBL, 0x196C3671L, 0x6E6B06E7L,
		0xFED41B76L, 0x89D32BE0L, 0x10DA7A5AL, 0x67DD4ACCL,
		0xF9B9DF6FL, 0x8EBEEFF9L, 0x17B7BE43L, 0x60B08ED5L,
		0xD6D6A3E8L, 0xA1D1937EL, 0x38D8C2C4L, 0x4FDFF252L,
		0xD1BB67F1L, 0xA6BC5767L, 0x3FB506DDL, 0x48B2364BL,
		0xD80D2BDAL, 0xAF0A1B4CL, 0x36034AF6L, 0x41047A60L,
		0xDF60EFC3L, 0xA867DF55L, 0x316E8EEFL, 0x4669BE79L,
		0xCB61B38CL, 0xBC66831AL, 0x256FD2A0L, 0x5268E236L,
		0xCC0C7795L, 0xBB0B4703L, 0x220216B9L, 0x5505262FL,
		0xC5BA3BBEL, 0xB2BD0B28L, 0x2BB45A92L, 0x5CB36A04L,
		0xC2D7FFA7L, 0xB5D0CF31L, 0x2CD99E8BL, 0x5BDEAE1DL,
		0x9B64C2B0L, 0xEC63F226L, 0x756AA39CL, 0x026D930AL,
		0x9C0906A9L, 0xEB0E363FL, 0x72076785L, 0x05005713L,
		0x95BF4A82L, 0xE2B87A14L, 0x7BB12BAEL, 0x0CB61B38L,
		0x92D28E9BL, 0xE5D5BE0DL, 0x7CDCEFB7L, 0x0BDBDF21L,
		0x86D3D2D4L, 0xF1D4E242L, 0x68DDB3F8L, 0x1FDA836EL,
		0x81BE16CDL, 0xF6B9265BL, 0x6FB077E1L, 0x18B74777L,
		0x88085AE6L, 0xFF0F6A70L, 0x66063BCAL, 0x11010B5CL,
		0x8F659EFFL, 0xF862AE69L, 0x616BFFD3L, 0x166CCF45L,
		0xA00AE278L, 0xD70DD2EEL, 0x4E048354L, 0x3903B3C2L,
		0xA7672661L, 0xD06016F7L, 0x4969474DL, 0x3E6E77DBL,
		0xAED16A4AL, 0xD9D65ADCL, 0x40DF0B66L, 0x37D83BF0L,
		0xA9BCAE53L, 0xDEBB9EC5L, 0x47B2CF7FL, 0x30B5FFE9L,
		0xBDBDF21CL, 0xCABAC28AL, 0x53B39330L, 0x24B4A3A6L,
		0xBAD03605L, 0xCDD70693L, 0x54DE5729L, 0x23D967BFL,
		0xB3667A2EL, 0xC4614AB8L, 0x5D681B02L, 0x2A6F2B94L,
		0xB40BBE37L, 0xC30C8EA1L, 0x5A05DF1BL, 0x2D02EF8DL
};

class CCRC16
{
	CRC16_CTX m_context;
public:
	enum { nDigestLength = 2};
	int Init()
	{
		m_context = 0xFFFF;
		return 0;
	}

	int Update(unsigned char * pData, unsigned int ulLen)
	{
		unsigned long i = 0;

		for(i = 0; i < ulLen; i++)
			m_context = (m_context >> 8) ^ crc16tab[(m_context ^ *pData++) & 0xFF];
		return 0;
	}

	int Final(unsigned char *pszOut)
	{
		m_context = ~(m_context);
		pszOut[0] = (unsigned char)((m_context & 0xFF00 )>> 8);
		pszOut[1] = (unsigned char)((m_context & 0xFF ));
		return 0;
	}
};

class CCRC16CCITT
{
	CRC16CCITT_CTX m_context;
public:
	enum { nDigestLength = 2};
	int Init()
	{
		m_context = 0xFFFF;
		return 0;
	}

	int Update(unsigned char * pData, unsigned int ulLen)
	{
		unsigned long i = 0;

		for(i = 0; i < ulLen; i++)
		{
			m_context = (m_context >> 8) | (m_context << 8);
			m_context ^= pData[i];
			m_context ^= (m_context & 0xFF) >> 4;
			m_context ^= (m_context << 8) << 4;
			m_context ^= ((m_context & 0xFF) << 4) << 1;
		}
		return 0;
	}

	int Final(unsigned char *pszOut)
	{
		m_context = ~(m_context);
		pszOut[0] = (unsigned char)((m_context & 0xFF00 )>> 8);
		pszOut[1] = (unsigned char)((m_context & 0xFF ));
		return 0;
	}
};

class CCRC32
{
	CRC32_CTX m_context;
public:
	enum { nDigestLength = 4};
	int Init()
	{
		m_context = 0xFFFFFFFF;
		return 0;
	}

	int Update(unsigned char * pData, unsigned int ulLen)
	{
		unsigned long i = 0;

		for(i = 0; i < ulLen; i++)
			m_context = ((m_context) >> 8) ^ crc32tab[(pData[i]) ^ ((m_context) & 0x000000FF)];
		return 0;
	}

	int Final(unsigned char *pszOut)
	{
		m_context = ~(m_context);
		pszOut[0] = (unsigned char)((m_context & 0xFF000000 )>> 24);
		pszOut[1] = (unsigned char)((m_context & 0xFF0000 )>> 16);
		pszOut[2] = (unsigned char)((m_context & 0xFF00 )>> 8);
		pszOut[3] = (unsigned char)((m_context & 0xFF ));
		return 0;
	}
};
#endif